Receiver



June '30, 1925.

G. G. CROMARTIE ET AL RECEIVER Filed Aug. 22 1923 Fetented dune 3'1 1925.

were srarss PATENT crates.

GEORGE G. CROMARTZE, OF EAST ORANGE, ANIIEINAB W. NIELSEN, OF NEWARK,

NEW JERSEY.

RECEIVER.

Application filed August 22, 1923. Serial No. 658,659.

To all to 7mm it may concern Be 1t known that we, Gnonen G. Gno- MARTIE and EINAR W. NIELSEN, residing at East Orange and Newark, respectively, in the county of Essex and State of New Jer sey, have lnvented certain new and useful Improvements in Receivers, of which the following is a specification.

This invention relates to receivers adapted for converting electrical impulses into sound. waves and is particularly useful in receivers .of the watch-case type used in wireless telephony.

It the principal object of our invention to provide a receiver which is very simple in construction and consequently cheap to manufacture, yet one that is highly efficient. Another object of our invention is to provide a construction in which the terminals on the cord connecting the receiver in cir cuit, are completely enclosed within the re ceiver casing-so that these parts are not exposed to injury.

Another object of our invention is to pro vide a receiver in whichthe construction tends to produce the minimum wei ht so 7 that the receiver will be more comfortable on the operators head.

These and other objects will be apparent after a study of the Specification and draw ing in which:

Figure 1 is a plan view of our receiver 'with the diaphragm and ear piece removed,

showing the cord terminals in position.

FigureEZ is a longitudinal sectional View through Fig. 1.

Figure 3 is a perspective view of one of the electromagnets showing the unitary construction of the cord terminal mounted it on one of the electromagnet heads, and

Figure 4- is a view of one of the magnets used in the receiver.

Referring now to the details wherein like numbers refer to corresponding parts in the various views,-1 is a casing which may be of any suitable material such as aluminum,

which I prefer to use inorder to give lightness. Attached tothe top part of the cats ing 1 is the usual ear piece 2, which clamps adiaphragm The interior bottom part of the casing 1' has a channel whlch may extend diametrically across the casing. The

exterior bottom part, it will be seen, is perfectly flat with no protruding parts. Situated in the central portion of the channel, but near the side wall of the casing 1 and 2, are studs or rivets l which may be moulded or cast integral therewith, or as will be apparent, holes may be provided in the bottom of the casing and the rivets passed therethrough. In either event,the studs or rivets 1, or their equivalent, engage the casing in such a manner as to hold the magnets 7 and core members 5 and 6 in position. The core pole pieces 5 and 6 are substan tially L-shaped, one leg of each sitting in the cross channel. The thickness of the pole pieces 5 and 6 is such that they come substantially flush with the bottom of the casing, so that the permanent magnets 7 will firmly engage their extremities, which are positioned, through the medium of holes 8, over the studs 4-; the magnets 7 preferably having their ends arcuately formed at 9 to fit. around the studs 4:.

As shown in Fig. 2, the complete magnet utilizes fourpieces similar to that indicated inFig. 4, although it will be understood that the magnet may be made thicker and only two pieces be used, one on either sideof the receiver. The magnets 7 closely fit the in terior casing of the shell and after they, together with the 'electromagnet cores on which the windings 10 are preferably assembled, have been put in place in the shell, the upper end of the studs 1 are peened or spun over as indicated at 11, whereby the material of the stud or rivet is expanded so as to force the magnets against the wall of the casing, thereby holding them securely in position. The electromagnets 10 have heads 12 and 13 preferably of insulating material. 011 the head 13 of each of the eloctroma nets, is fastened a connector 14 by meansc'. a rivet or eyelet 15. Vhere the casing 1 is metal, such as aluminum for the purpose of lightness, we prefer in winding the electromagnets to skin the insulation from the inner ends and wind a number of turns of the bare wire directly on tothe core, then a piece of insulation is placed between these inner grounded layers and the succeeding insulating layers. The outer extremity of the winding 16 is then brought out and soldered to the eyelet or base of the connector before the coils and cores are put in place on the receiver, so that it will be seen no soldered joints are required to be made in the receiver at any station of the assembly operation. It'will be readily seen that this construction substantially eliminates the breaking off of the inner turns of the winding as is very frequently done where these ends are brought out and required to be twisted together and soldered,:since during these operations, the small wires arevery apt to be broken off; and hence the cost of manufacture of the electromagnets of our receiver is reduced to a minimum. Of course, it will be understood that where the casing 1 is of insulating material the channel carrying the four pole pieces 5 and 6 will extend all the way across the bottom of the receiver and a thin copper strip may be placed beneath the core. pole pieces which will tie them together electrically, completingthe electric circuit through the winding of the coils. The connector 14 is substantially U-shaped and is made of spring material, having holes in each of the arms of the U, while holes are adapted to take cord terminals 17 which, when inserted in the holes, are gripped by the arms of the connector so as to hold the terminals securely in position.

In order to take the pull or strain on the.

cord 18 oil from the terminal 17 and the connectors 14, a strain member 19 made from the fabric of the cord is carried inside the leave a bridge in the central portion of the receiver in order to strengthen the bottom of the receiver at this particular point. The

bridge is indicated in Fig. 2, while the complete channel is indicated by a dotted line 21 in Fig. 1. i

It will be noticed; that there are no screws or tapped holes in our receiver, the only threads being on the top part of the casing receiving the ear piece. The elimination of screws and all tapping for screws reduces the cost of manufacture materially. and eli1ninates the parts ,which sometimes give trouble due to the loosening of screws.

It will also be apparent to. one skilled in theart that certain changes may be made in the details of my invention without departing from the spirit of the same and the scope otthe appended claims.

magnets .resting on the bottom of the casing and having their polar ends overlapping and engaging said core ends in the channels and substantially encircling said studs, said studs being rivetted over to clamp the magnets and core members to the casing and windings on the arm of each of said core members.

2. In a device of the class described, a

' casing, diaphragm and ear piece, said casing having a pair of studs integral therewith but arranged on a diameter a short distance from the side wall of the casing, a pair of magnet cores each having a part seated on the bottomot the casing and fitting around one of the studs and another part having a winding thereon extending upward to cooperate with the diaphragm,magnets positioned on the bottom of the casing and having their polar ends overlapping said core end that rests on the bottom of the casing, said studs being riveted over to hold said magnets and core and to the casing.

3. In a device of the class described, a casing, diaphragm and ear piece, magnets disposed within the casing, core pieces fastened to and extending from the poles of pieces in working position said magnets to points adjacent the central portion of said diaphragm, spool heads on the cores and windings between sa1d heads and means carried by two of sa1d heads for attaching the extremities of the windings as well as cord terminals. V

4. In a device of the class described, a casing, diaphragm and ear piece, said casing having a centrally arranged cross channel, a pair of L shaped magnetic coremembers having an arm of each set in said channel and substantially flush with the bottom of the casing,'magnets resting on thebottom of the casing and having their polar ends overlapping and engaging said core ends in the channel, means for fastening the magnets and core members to the casing, spool heads on the other arms of said core members with windings between said heads, terminal clips on two of said spool heads to which the outer extremities of the windings and. cord terminals may be connected.

'5. In a device oflthe class described, a casing, diaphragm and ear piece, magnets and core polepieces fastened tothe interior bottom of the casing, said pole pieces having arms extending-into operative relationship llO with the diaphragm, protecting heads on said arms with windings thei ebetween, one pair of said heads having terminalclips carried thereon to which the outer extremities of said winding and cord terminals are at-- tached; V r

6. In a device at the class described, aoasing, diaphragm and ear piece; magnets fastened to the interior of the casing and a pair of unitary electro-magnetic structures disposed between the poles of the magnets and the diaphragm; said unitary structures consisting of; L shaped cores with. windings on one arm and heads of insulating material for holding the winding'in place on the arm, a pair of heads carrying terminal clips to which the outer extremities of the winding and cord terminals are connected.

7. In a device Or the class described in cluding a casing, magnet, diaphragm and ear piece; a pair of unitary electromagnet structures each consisting of; a magnetic core member extending from the poles of the v magnet into operative relationship with the diaphragm, a winding on said core, heads of insulating material to hold the winding 1n alace a terminal cli carried directl on- 1 a one of said heads and having an extremity of the winding attached thereto, said clip also being adapted to receive a cord terminal.

8. In a device of the class described including a casing, magnet, diaphragm and ear piece; a pair of unitary electromagnet structures each consisting of; a magnetic core member extending from the poles o1 the magnet into operative relationshipwith the diaphragm, a winding on said core,

heads of insulating material to hold the winding in place, a U shaped spring terminal clip carried on one of said heads and having an extremity of the winding attached thereto, said clip having holes near the outer ends of its arms whereby a cord terminal inserted in said holes will be gripped by the spring tension of the clip arms.

9. In a device of the class described including a casing, magnet, core pole pieces, diaphragm and ear piece, a winding for each or said cores, protecting heads for the windingand "means on one of the heads for attaching thereto an extremity of the winding and a cord terminal.

of; terminal, clips mounted on one pair of said heads, said clips having an extremity of the winding connected thereto and also adapted to have fastened thereto an incoming ircuit terminal.

11.- In a device of the class described including a casing, magnet, core pole pieces, diaphragm and ear piece, a winding for each of said cores, protecting heads for the winding and means for making quick outside electrical connectioiiwith the windings comprisi'nga member carried on each of two or said heads, said member having two resilient parts with co-acting means for quickly engaging but securely holding the incoming conductor end, said member also adapted to have an extremity of one of the windings connected thereto.

12. In a receiver for the purposes described, a casing containing, a magnet diaphragm and electro-magnets disposed between the magnet and diaphragm, means for making electrical connections with said electro-n'iagnets, including holes in the wall of the casing through which conductors may pass and means mounted directly on the heads of said electro-magnets for attaching said incoming conductors as well as the ex tremities of the winding of the electromagnets.

18. In a receiver for the purposes described, a casing containing, a magnet diaphragm and electro-magnets disposed between the magnet and diaphragm, means for making electrical connections with said electromagnets, including holes in the wall of the casing through which conductors may pass, means mounted directly on the heads of said electro-magnets for attaching said incoming conductors as well as the extremities of the winding of the electromagnets, said casing having an additional hole in the wall through which a strain cord may pass and be anchored on the interior of said casing.

14:. In a device of the class described, a casing, diaphragm and ear cap, a pair of magnet core members positioned within the casing, each of said core members carrying a winding adjacent the diaphragm, magnets within said casing and having their polar ends in engagement with said core members and means engaging the casing and passing between the magnet ends and adapted to be expanded so as to force the magnets securely against the wall of the casing.

15. In a device of the class described, a casing, diaphragm and ear cap, a pair of magnet core members positioned within the casing, each of said core members carrying a winding adjacent the diaphragm, magnets within said casing and having their polar ends in engagement with said core members and means engaging the casing and passing through said core members but between the magnet ends and adapted to be expanded so as to force the magnets securely against the wall of the casing.

16. In a device of the class described, a casing, diaphragm and ear cap, a pair of ends in engagement with said core members,

magnet core members 'positioned within the tween the magnet ends, said rivet members casing, each of said core members carrying being adaptedto beexpanded so as to force a winding adjacent the diaphragm, magnets the magnets against the Wall of the casing, within said casing and having their polar In testimony whereof we affix our sigma-i tures.

' GEORGE G. CROMARTIEQ BINAR W.-NIELSEN.

rivet members carried by the casing and passing through saidcore membersbut be 

